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Justin Bieber has explained why he broke down in tears at the end of his 2015 MTV Video Music Awards performance Sunday night.

"It was just so overwhelming for me ... everything, the performance," the 21-year-old singer told Jimmy Fallon on Wednesday night on "The Tonight Show."

At the VMAs, following a performance of "Where Are U Now" and his new single, "What Do You Mean," the Biebs got teary-eyed. He explained to Fallon that he was blown away by the positive response from the audience, especially given that the last time he appeared on an awards show, at Fashion Rocks in September 2014, he was booed.

"I worked so hard at the album. I've worked so hard at just becoming the man that I want to become and then stepping into situations you can't help but feel judged," Bieber said. "What was so special about the emotional moment, it was authentic and real. I was just wanting it so bad."

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He blamed his past troubles on being surrounded by "knuckleheads."

"I just went through a place of just trying to figure it out," he said. "You have to figure out what you are OK with and what you're not OK with, but you have to test the waters. I just happened to be ... in the spotlight in front of cameras all the time."